Leishmaniasis is a disease caused by infection with a protozoan of Leishmania genus (see, for example, IKAGAKU DAIJITEN 49, ENCYCLOPEDIA OF MEDICAL SCIENCES, published in April 1993, Kodansha). More than 12,000,000 people are estimated to be suffering from this disease. Leishmaniasis is one of the important diseases designated by WHO. The leishmania protozoans are classified morphologically into two types: amastigote and promastigote. The both types of protozoans are known to promulgate as the promasitgote type when the protozoan is transplanted to an appropriate culture medium.
Three species are known to infect humans: Leishmania donovani, Leishmania tropica, and Leishmania braziliensis.
These three species have not been differentiated from each other morphologically. However, in recent years, these species have come to be known to include subspecies and varieties by immunological and biochemical techniques.
The methods for detection of the pathogen include direct detection of the protozoan, and indirect estimation of infection with the protozoan by immune reaction or a like method.
Of these, the direct detection is sure, but requires long time and complicated operations, being not practicable in a short time and in large numbers.
The known indirect detection methods include Chopra's antimony reaction, Napier's aldehyde reaction, Branchari's euglobulin reaction, and so forth.
Further, complement-fixation reaction, indirect hemagglutination reaction, and indirect immunofluorometry are known as the immunological methods therefor.
The definite identification of the species is conducted by using cultivated protozoan by Adler's test, measurement of buoyant-density of kineplast DNA, isozyme analysis, and so forth as well as the immune reaction.